WASHINGTON –- Hundreds of Marines are expected to arrive in the typhoon-stricken Philippines by the end of the week to bolster a relief effort that has struggled against logistical hurdles and overwhelming devastation, U.S. officials said Wednesday.

The deployment of Marines from Okinawa, Japan, adds to the growing U.S. humanitarian mission after Typhoon Haiyan, one of the strongest storms ever to make landfall, hit the Philippines early Friday, killing hundreds of people and leaving hundreds of thousands homeless. The official death toll Wednesday was 2,275, with aid workers fearful that it would continue to grow.

The additional troops are expected to push the number of U.S. military personnel assisting with relief efforts in the Philippines from 300 to more than 1,000, officials said.

In the last two days, the first U.S. shipments of plastic tarps, hygiene kits, blankets and medical supplies reached the hard-hit coastal city of Tacloban, ferried by KC-130 cargo jets and MV-22 tilt-rotor aircraft from Clark Air Base, a former U.S. Air Force installation near Manila, the Philippine capital.

Nearly 274,000 pounds of supplies had reached Tacloban by day’s end Wednesday, said two senior Obama administration officials who briefed reporters on condition of anonymity. U.S. military personnel had also evacuated about 800 people from Tacloban to Manila for medical treatment.

One official said the relief effort was “starting to turn the corner.”

The U.S. is focusing on getting assistance to destroyed coastal villages, providing food and water and staving off the spread of water-borne diseases.

The humanitarian emergency hub, the tiny airport in Tacloban, can handle only midsized planes. But U.S. officials said that an overland route to the city had been opened and that supplies soon could reach Tacloban by road from a nearby port.

Relying on the airport was “like trying to squeeze an orange through a straw,” said one U.S. official. “We are now getting more straws and bigger straws.”

The U.S. government has pledged $20 million in aid, and the United Nations has issued a worldwide appeal for $301 million in emergency assistance for the 11 million people it estimates have been affected by Haiyan.

Officials said that Philippine security forces have begun to tamp down insecurity and looting by deploying additional soldiers and declaring curfews. But gas station owners and others who have fuel to sell have been reluctant to open their pumps, fearing they would be looted or attacked by desperate civilians, making it harder for relief convoys to gas up their trucks.

The fuel shortage was “very much on the radar screen,” the official said, but it was up to the Philippine government to tackle that problem.

“The violence and insecurity … that was really driven by the desperation of people to get assistance,” the official said. “Now, as we are handling some of these logistical hurdles and the volume of assistance is starting to spike upwards, we imagine that will dissipate pretty quickly.”

The destruction in the city of Tacloban caused by Typhoon Haiyan, which struck a wide swath of the Philippines, is shown in these before-and-after photos. Use the slider handle to reveal the images. More photos